#define _CRT_SECURE_NO_WARNINGS 1
#include <climits>
class Solution {
private:
    class Sum
    {
    public:
        Sum()
        {
            sum += val;
            val++;
        }
        static int val;
        static int sum;
    };

public:
    int Sum_Solution(int n) {
        Sum a[n];
        return Sum::sum;
    }
};
int Solution::Sum::val = 1;
int Solution::Sum::sum = 0;